A great deal of attention has been focused in recent years on sanitizing the surfaces of areas where the growth of microbial populations can pose a serious hazard to human health. Such areas can include hospitals, food preparation installations, food manufacturing areas, biological substance manufacturing areas, and others. The surfaces requiring sanitization can be treated with a variety of sanitizing agents. Such agents can take the form of solutions of small molecule bacteriocides, bacteriostatic agents, and others. Alternatively, the sanitizing agents can take the form of polymeric agents that can form sanitizing coatings on the surfaces.
Polymeric compositions containing quaternary ammonium moieties have been used in many sanitizing environments. Quaternary ammonium compound containing polymeric substances have been used in a variety of different forms. A water insoluble reaction product of a quaternary ammonium compound and a carboxylic acid functional polymer composition has been placed in solution in a compatible organic solvent and applied to surfaces to form a film. The prior art also recognizes that such water insoluble reaction products can be formed by contacting, for example, a fabric or an activated carbon particle, first with an aqueous polymer solution and second with an aqueous quaternary ammonium compound solution. In this way the insoluble product forms on the fabric surface or in the activated carbon particle. Alternatively, polymers can be made from monomers containing a quaternary ammonium moiety. For example, copolymers can be prepared from monomers such as a copolymerizable vinyl benzyl quaternary ammonium salt compound or from a quaternary ammonium salt compound having one or more ethylenically unsaturated groups attached directly to the ammonium nitrogen.
We have found in our developmental work that the insoluble precipitates, formed by reacting a quaternary ammonium compound and a carboxylic acid containing polymers, are difficult to handle in a solid composition or in water based form. Further, the compositions which can be used and applied from organic solvent can be expensive and can be hazardous in view of the toxicity and flammability of certain useful solvents. Lastly, the polymers made from quaternary ammonium containing monomers appear to have reduced sanitizing properties that appear to relate to the reduced solubility of the polymer.
Accordingly a substantial need exists for developing an easily applied sanitizing polymeric film made from a carboxylic acid functional polymer and a quaternary ammonium compound.